NAME¶
gdnsd-plugin-extfile - gdnsd plugin for importing monitor data via file
SYNOPSIS¶
Example service_types config:
service_types => {
ext1 => {
plugin => "extfile",
file => "/var/tmp/ext1data", # required
direct => true, # default false
def_down => false, # default false
def_ttl => 600, # default max (limited by zonefile RRs)
}
ext2 => {
plugin => "extfile",
file => "ext2data", # def dir: /var/lib/gdnsd/extfile/
},
}
Example plugin config using these service_types:
plugins => {
multifo => {
www1 => {
service_types => ext2,
lb01 => 192.0.2.200,
lb02 => 192.0.2.201,
lb03 => 192.0.2.202,
}
www2 => {
service_types => [ ext1, http_status ],
lb01 => 192.0.2.203,
lb02 => 192.0.2.204,
lb03 => 192.0.2.205,
}
},
weighted => {
wwwcn => {
service_types => ext1,
lb01 = [ lb01.example.com., 99 ],
lb02 = [ lb02.example.com., 15 ],
lb03 = [ lb03, 1 ],
}
wwwz => {
service_types => ext1,
lb01 => [ 192.0.2.203, 10 ],
lb02 => [ 192.0.2.204, 15 ],
lb03 => [ 192.0.2.205, 20 ],
}
}
}
Example extfile data defining the resource + service_types specified above:
/var/tmp/ext1data:
192.0.2.203 => UP/300
192.0.2.204 => DOWN/242
192.0.2.205 => DOWN/102
lb01.example.com. => UP/60
lb02.example.com. => UP/30
lb03 => UP/45
/var/lib/gdnsd/extfile/ext2data:
192.0.2.200 => DOWN
192.0.2.201 => UP
192.0.2.202 => UP
DESCRIPTION¶
gdnsd-plugin-extfile is a monitor plugin that imports monitor results
from an external file (which is probably populated by some script/tool from
some other monitoring software).
MODES¶
An extfile service_type can operate in one of two basic modes:
- Monitor Mode (default)
- In monitor mode, the standard parameter "interval" is used as a
repeating timer. At each interval, the file is loaded for state updates
(but any direct TTL values in the file are ignored).
The updates from the file are fed into the standard core monitoring system
by the same mechanisms as normal monitoring plugins (e.g. http_status).
This means they will be subject to the standard anti-flap measures via the
standard threshold parameters ("up_thresh",
"down_thresh", "ok_thresh") before affecting the final
status seen by resolution plugins.
This mode is appropriate if the updates being processed are relatively-raw
updates from individual monitor checks.
- Direct Mode
- In direct mode, the standard parameter "interval" is used only
as a hint to the filesystem-watching code to try to check for
updates no less often than the supplied interval. However in many cases
(especially e.g. Linux with "inotify()" support) updates to the
file may be picked up much sooner, perhaps nearly instantly.
There will be a short (~1 second) settling delay after detecting any update
in order to coalesce any rapid-fire updates into a single transaction.
The results contained in the file (state and/or TTL per-resource) are
applied directly as final monitoring results and made immediately
available to resolution plugins for decision-making.
This mode is appropriate if the updates are from processed monitoring
results that have already been through e.g. anti-flap measures before
reaching gdnsd.
The file is formatted using the same "vscf" language that's used for
the main config file and the geoip nets databases. The expected data format is
a simple key-value hash at the top level, where the keys are the monitored IP
address or CNAME values from the monitor plugins and the values are of the
form form "state[/ttl]", where state is either "UP" or
"DOWN" and the optional ttl is an integer ttl value. TTL values are
only used for "direct"-mode service_types; the TTL is calculated in
the normal fashion based on intervals and thresholds for
"monitor"-mode.
CONFIGURATION - PER-SERVICE-TYPE¶
The universal, plugin-neutral service_type parameters all apply in their usual
sense: "up_thresh", "ok_thresh", "down_thresh",
and "interval" (keeping in mind the notes above about how each mode
uses "interval"). "timeout" is ignored. extfile-specific
parameters:
- direct
- Boolean, default false. Sets the monitoring mode to "direct" if
true, otherwise mode defaults to "monitor".
- file
- String filename, required. This sets the name of the file to load results
from. If the pathname is not absolute, it will be considered relative to
/var/lib/gdnsd/extfile/.
- def_ttl
- Integer TTL, default is max (which will be limited by zonefile RR TTL
values). In "direct" mode this will be set as the monitored TTL
if no optional TTL is supplied in the file data for a given resource. It
is ignored in "monitor" mode.
- def_down
- Boolean, default false. This sets the default disposition of configured
resources which are missing from the file data (which will generate
warnings). If true, these resources behave as if the file data marked them
"DOWN", otherwise they default to "UP".
SEE ALSO¶
gdnsd.config(5),
gdnsd(8)
The gdnsd manual.
COPYRIGHT AND LICENSE¶
Copyright (c) 2012 Brandon L Black <blblack@gmail.com>
This file is part of gdnsd.
gdnsd is free software: you can redistribute it and/or modify it under the terms
of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
gdnsd is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
gdnsd. If not, see <
http://www.gnu.org/licenses/>.